02 GLS lights flickering.
 

Basically the lights are flickering and the engine along with them when idling. If I am driving with the higher rpm's it smooths itself out. First I thought alternator, checked that and it was good. I tightened the belt slightly seemed to help out a little but, still flickering. If I turn the lights off the flickering smooths out slightly and the idol is smooth. If I turn the lights back on the dash dims slightly and it will start puttering just a tiny bit and the lights will flicker. If I rev up to about 2000 rpm's it will smooth out. If anyone knows where to start it would be greatly appreciated to recieve your knowledge.

Sounds like the engine idle speed is too low.